Hmmm, I'm working on the same project at a different location using a much smaller computer (C1D, 1.5GB memory) and at that system I too have -Xmx512M. There are no real problems there (yes, it's slow and all, but the JBoss editor doesn't really make it slower).
I'm pretty sure that the validation was disabled as well, but I'll double check whether it was that specific validator.